This invention relates to the folding of travelling film webs in a package forming system.
The automatic folding of a travelling web of sheet material during a change in its travel direction to form an envelop-type package is generally known. Folding formers performing the foregoing folding function usually fold the web along a single fold line parallel to the direction of travel during a single fold forming operation. Any additional folds required would ordinarily call for additional folding operations. Further, such folding operations are not readily adaptable to the folding of webs of different width so as to render the packaging equipment limited to single size packages.
The foregoing type of folding formers are particularly useful in packaging systems wherein sheets of collated material are wrapped in the web film during the folding operation in order to produce a packaged product. However, the package formed cannot be tailored in size to the sheets enclosed therein by any simple adjustment of the equipment. Further, in the absence of additional folding operations, seaming is limited to unfolded edge portions of the web material in the formation of the package.
It is therefore an important object of the present invention to provide a package forming folder device of the aforementioned type that produces at least two folds during a single folding operation on a travelling web and which is readily adjustable to accommodate webs of different widths in order to meet varying dimensional requirements for the package.